Stefanos Tsitsipas beat Damir Dzumhur, 6-1 6-4, at the Miami Open to set up a match with Kei Nishikori.
The Greek world number five needed just an hour and eight minutes to progress.
The Japanese veteran made his way through to the next round when he defeated Aljaz Bedene.
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Nishikori had to play through almost three hours to beat the Slovenian 31-year-old 7-6 (6) 5-7 6-4.
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Elsewhere, Milos Raonic had little difficulty beating Jordan Thompson 6-2 6-1, while Ugo Humbert will face him in the next round after beating Joao Sousa 6-1 6-4.
Marin Cilic defeated Cristian Garin over three sets, Sebastian Korda beat Fabio Fognini 1-6 6-4 6-2.
Daniel Elahi Galan beat Alex De Minaur 4-6 6-3 6-4. Experienced Frenchman Benoit Paire was sent home by teenager Lorenzo Musetti 6-3 6-3.
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